Electric vehicles, hybrid vehicles and fuel cell vehicles have been known as electric powered vehicles configured such that an electric motor for driving the vehicle can be driven by electric power from a power storage device mounted on the vehicle represented by a secondary battery. For an electric powered vehicle, a configuration for charging the power storage device mounted on the vehicle by a power source outside the vehicle (hereinafter also simply referred to as an “external power source”) has been proposed. In the following, charging of a power storage device by an external power source will also be simply referred to as “external charging.”
By way of example, Japanese Patent Laying-Open No. 2009-027774 describes a configuration of an externally chargeable vehicle, including a battery B1 chargeable from the outside of the vehicle, a DC/DC converter 33 lowering the voltage of battery B1, a battery B3 charged by the output of DC/DC converter 33, and an auxiliary load 35 receiving power supply from battery B3.
Particularly, in the configuration of PTL 1, DC/DC converter 33 is operated continuously while the vehicle is running, and DC/DC converter 33 is operated intermittently in accordance with the voltage output from battery B3 while the vehicle is externally charged. This improves charging efficiency at the time of external charging.